Method of multiple control.



H. w.- LEONARD. METHOD OF MULTIPLE CONTROL.

APPLICATION FILED MAY 9, 1901.

6 SHEETS-SHEET 1.

Patented Sept. 19, 1911;

Inventor Witnesses:

H. W. LEONARD.

METHOD OF MULTIPLE CONTROL. APPLICATION FILED MAY 9, 1901.

Patented Sept. 19, 1911.

6 SHBETSSHEET 2.

Inventor Att'ys.

w M W zngsses: I

H. w. LEONARD. METHOD OF MULTIPLE GONTROL, I APPLICATION TILED MAY 9,1901;

1,003,923. Patented Sept. 19,1911.

6 SHEETS-SHEET a;

Witnesses: A Inventor W. LEONARD. METHOD OF MULTIPLE CONTROL.APPLICATION FILED MAY 9, 1901.

Patented Sept. 19, 1911.;-

6 sums-sum 4.

W. LEONARD. METHOD OF MULTIPLE CONTROL.

APPLICATION FILED MAY 9, 1901.

1,003,923. Patented Sept. 19,1911;

6 SHEETS-SHEET 6.

Witnesses Inventor Att'ks.

H. W. LEONARD. METHOD OF MULTIPLE CONTROL. APPLIOATION FILED mu 9, 1901.

6 SHEETS-SHEET 6.

5 mac nlroz HARRY WARD LEONARD, OF NEW YORK, N. Y.

METHOD OF MULTIPLE CONTBZOL.

Specification of Letters Iaten't.

Patented Sept. 19, 1911.

Original application filed January 24, 1901, Serial No. 44,565. Dividedand this application filed Kay 9,

To all whom it may concern:

Be it known that I, HARRY WARD Leon- ARI), a citizenof the UnitedStates, residing in the borough of Manhattan, city of New York, State ofNew York, have invented a certain new and useful Improved Method ofMultiple Control, of which the following is a description.

My invention relates to electric transmission of power, and my principalobject isthc operation of electric translating devices in such a waythat one or more of such devices can be controlled from severaldifferent points.

The present application is a division of my application tiled January24th 1901, Serial No. 44,565.

One of the most important applications of my present invention is thesimultaneous control of a plurality of electric motors located upondifferent cars composing a train, so that from any one of severaldifferent cars the motos can be operated at any desired speed and ineither direction, while at the same time they will operate in .harmony,dividing the load approximately in proportion to their capacity. Myinvention is also capable of use in the operation of electric motorsused for other purposes, asfor 'example in connection with pumps,swinging bridges, elevators, cranes, guns, propel.- lers, rudders, metalrolls, moving sidewalks, printing presses, cable power transmittingdevices, as well as valves and-governors of engines, turbines, etc. Myinvention is, however, not limited to the control of electric motors,but may be utilized in controlling the voltage or the current suppliedto other electric translating devices, such as electric lights, electricheaters, rheostats, circuit controllers, electric furnaces, storagebatteries, electrolytic cells, and in fact mechanism in general operatedor controlled from several points through the agency of electric energy.

My invention is of particular importance with reference to the controlof motors of the commutator type and with regard to the advantagessecured of a smoothly graduated control of the speed which are not so advantageously obtainable with motors of other In motors of the commutatortype, however, there are difficulties with regard to the commutation dueto flashing over, insulation, destructive sparking, etc., unless theelectromotive force of 'the energy to be Serial No. 59,373.

commutated is kept below certain limits de: pendent upon the design ofthe motor. It is, therefore, very desirable in conjunction withtransmitting and collecting energy at high pressures, to transform suchhigh pres-' sure energy upon the train (when my invention is used inconnection'with railways,) to energy of sufficiently low electromotiveforce so that the objections to commutation may be avoided and securethe said advantages as to refined, gradual and economical control of themotors.

One of the important results due to the employment of my invention, isthat the rigid wheel base is reduced as compared with that required ifall the power were developed in one locomotive unit, where all themotors act on a rigid wheel base.

Another particular feature is that when a plurality of locomotive unitsare employed according to my invention, the dimensions of the severalvoltage regulators are of course less than would be the case if only onewere employed for the total power, and this enables me in the limitingcase to apply a. greater power to a train. Even if there be but onevoltage regulator for two or more locomotive units I gain greatadvantage as to maximum. traction where conditions are such as to tendtocause certain of the drivers to skid without the skidding of others bythe fact that the motof'armat-ures are in parallel and not in series,and there is also advantage as to maximum traction due to the fact thatthe motors have field windings which are separately excited. A certainpower controllably divided between a plurality of on a certain roadbed;and makes it possible to operate on curves of shorter radius. In caseswhere turn-tables are employed, they may be comparatively small andt-hestorage capacity of certain side tracks can be more advantageouslyemployed at terminals and similar places, and the locomotive units maybe more readily handled at the terminals.

Also the-trains may be more easily broken up and assembled as the dutyrequires. The risk of derailment is reduced, and the wear and tear uponthe roadbed is-also reduced.

Also the" first cost and'the cost of 1naint e'.

named the track is reduced compared with a system in which singlelocomotives are used of the aggregate power of my units.

In order that my invention may be better understood, attention isdirected to the accompanying drawings forming part of this specificationand in whieh Figure 1 1s a diagram illustrating two cars connectedtogether to form a train, each being equipped with two operating motorsand each being provided with corresponding controlling mechanism, theorlginal source of power being illustrated Is a; 3-

trating the connections which may be em-.

ployed when the current through the generator field or other device isto be controlled from several different points but not reversed, and inwhich case three wires only are necessary; Fig. 4 a corresponding viewillustrating two connected cars, each equipped with two propellinmotors, a dynamo electric generator, an? an exciter of variable andreversible electromotive torce,v

the original source of current being indicated as a 3-phase circuit, andwherein also only three wires between the cars are necessary; Fig. 5acorresponding view showing two cars, the propelling motors of which arecontrolled by the counter electromotive force system described andclaimed in m Patent No. 572,903, the original source 0 current beingcontinuous; Fig. (3 a corresponding view showing a system substantiallylike that illustrated in Fig. 1 except that the exciter is driven by aseparate small motor, in the present instance a 3-phase motor; and Fig.7 is a diagram corresponding to the disclosures'of Fig. 4, except that asingle phase supply of energy is indicated.

Referring first to Fig. 1, two cars I, II are diagrammaticallyillustrated, the first being propelled by motors M M, and the latterbeing propelled by motors M M". The.

cars are mechanically connected to form a train, and are electricallyconnected for the control of the several motors, as will be explained. Atrain may obviously be composed of more than two cars. The source ofcurrent illustrated is a 3-phase circuit extending parallel to the trackand with which collecting devices T and T on the cars are V the handleof the reversing rheostat in constant. contact. If desired, the 3 -phase circuit may be supplied with current from a feeding circuit FCconnecting either di rectly to the 3-p11ase circuit or by means of astep-down static transformer L. On each of the, cars I illustrate motorsA A respectively, which may be; 3-phase motors of the desired'capacityand receive current either directly from thecollecting devices T T orthrough the intermediate static transformers S S The armature shaft ofthe motor A drives a continuous current generator'G, and thefarmatureshaft of the motor A drives a continuous current generator G Thearmatures of the motors M M are connected in. parallel and receivecurrent from the generator G. The armatures of the mt)- tors M M arealso connected in parallel and'receive current from the generator G Eachof the cars is provided with four conducting wires 1, 2, 3, 4, which areadapted to .be'connect-ed by suitable couplings with the correspondingwires of the adjacent cars, as shown. 'The fields of all the motors M MM M are connected across the wires 1, 2. The fields of the generators GGr are connected across the Wires 3, 4. The armature of the motor Adrives a small generator or exciter E, while a corresponding generatoror exciter' E is drivenby the motor A The armature Q of the exciter E isconnected across the wires 1, 2, and the.

armature C of the exciter E is connected across the same wires,wherebythe circuit- 1-2 will be supplied with a current of constantelectromotive "force from eitherexciter, feeding thefields of theseveral propelling motors.

tromot-ive force supplied to the fields of the propelling motors isconstant, and that the current supplied to the fields of the generatorsG Gr is variable and reversible, whereby the propelling mot-or's may becontrolled in speed and direction. Thus, assuming both the motors A andA to be operatin that 2 occupies a neutral position, and that thebrushes of the exciter E are raised, sothat no current will be suppliedby-that exciter: Byproperly manipulating the handle of the rheostat Rthe current supplied to the circuit 34, and consequently to the fieldsof the generators G and G canbe correspondinglyincreased or reduced orreversed, whereby the electromotive force, as well as the'direction ofcurrent supplied by said generators to the armatures of the propellingmotors, is under absolute control.- In th s way it is possible to secureany desired speed 5 up to maximum in either directlon of rotation of themotors M M and M? M", and if these motors are practically identical,they will at all times divide the load equally between them. It maysometimes be neceso sary to adjust the brushes or the field strength ofthe propelling motors In order that they may be made practicallyidentical in capacity, but after such adjustment they will continue todivide the load equally,

commercially speaking, even when the speed is varied greatly or when thedlrection reversed. In Fig. 4,'to which I shall presently refer, Iillustrate small rheostats in thefields of the propelling motors, bywhich they may be adjusted in the first instance so as to divide theload proportionately or to compensate for any variation which may takeplace between them in use, as for ex ample when the wheels driven by onemotor may become worn and thereby become smaller in diameter.

If, instead of operating the reversing rheostat R, its handle is set tothe neutral position and the brushes of the exciter E are raised andthose of the exciter E 'are again engaged with its commutator, amanipulation of the reversing rheostat R will effect a control of theelectromotive force and direction of the current supplied by the exciterE to the circuit- 3-l so as to simultaneously vary the strength orreverse the fields of the generators G and G whereby the speed of theseveral propelling motors can be controlled simultaneously from the 40car III;

While I have illustrated and have referred to a 3-phase motor on eachcar forthepurpose of driving the continuous currentgenerator G or G itwill be obvious that in many cases any other motor, electric ormechanical, can be utilized for this purpose. When it is desired to stopthe train or a single car equipped as explained, the opera tor (assumingthe rheostat R to be in use) moves the operating handle thereof throughthe whole extent of its resistance until the handle reaches the neutralposition, thereby resulting in a gradual reducti on of the current inthe circuit3-4, effecting a gradual reduction of the fields of thegenerators G and G and effecting a consequent reduction in theelectromotive force supplied to the propelling motors. When theoperating handle of the rheostat reaches its neutral po- 50 sition, nocurrent will be supplied to the circuit 34 or by the generators G and Grto the propelling motors. Under these conditions of weakening the fieldsof G and G if the electromotive force of G and G falls below theelectromotive force generated by the armatures of M and M the propellingmotors become generators and supply current to the generatgu-s fi" and Gwhichact as motors todrive the motors A r A as generators supplyincurrent into the supply circuit, thereby recucing the energyrequired'for the operation of other trains on the same line from theoriginal source of power,'andinakingf'it possible to stop the locomotivewithout mechanical brakes. To-reverse the direction of movement, thejoperator moves the handle of the rheostat R or R as the case maybe, pastthe central or neutral position, ;thereby reversing the fieldmagnetismof the. generators G 211N180- G? simultaneously, and if the rheostathandle is further moved to cut out more 'or less of the resistance, theelectromotive force of the generators will gradually and simultaneouslyincrease up to the maximum in 5 the reverse sense, thereby graduallyincreasing the speed of the propelling motors in the opposite direction.

In Fig. 2, I illustrate a train comprising. three cars A, B, C, throughall of which extend the circuit wires 1, 2 forming the constantelectromotive force circuit, and the circuit wires 8, 4 forming thevariable and reversible electromotive force circuit. The

car 0 is ilustrated fas being. furnished only I wlth a single reversingrheostat R by'means 1 of which current fromthe circuit l-2 can ibesupplied to the circuit 3.4 varied in amount or reversed in sense,as-will be understood. The car B is provided with a reversing rheostat Rsimilarly connected, but said car is shown also as being equipped withpropelling motors M M the fields of which are connected in parallel withthe circuit 1+2, and the 'armatures of which are connected in parallelwith a circuit supplied from the generator G of the car A. The car A isprovided with the same-equipment as the cars shown in Fig. 1, exceptthat the static transformer between the collecting de- .vices T andthemotor A is. not illustrated.

It will be seen that by manipulating either of the rheostats R, R or Rthe operating handles -of the other rheostats being maintained in aneutral position, the current supplied to the circuit 3 4; can be variedor v reversed, thereby effecting a reduction in the field strength ofthe generator G or securing a reversal of that field to secure anydesired variation in the elect-romotive force or direction of currentsupplied to the several propelling motors, whereby their speed will besimultaneously increased or diminished, while at all times they willmaintain their proper proportion of the load. In this way the train as awhole can be efi'ectively controlled from any one of the cars.

Referring to Fig. 3, I illustrate an arrangement of circuits whereby a.translating de vice, illustrated diagrammatically as a magnet (1, may becontrolled from an i one of a number of points A, B or C, whic maycoring device d is connected in parallel. It willbe seen that byoperating either of the rhebstats e, e or e the others being open, the

current supplied to the translating device can be increased ordiminished at will to properly control the latter and any devicesaffected by it.

In Fig. 4, I illustrate means for controlling a plurality of motors orother electric translating devices, both as to their speed and as to thedirection of rotation of their armatures or other movable elements, fromany point on a curcuit of three'wires. The controlling motor a is ofanysuitable type, electric or mechanical, but for the purpose ofillustration Ihave represented it as a 3- phase motor supplied by acircuit LG-5' 6 The motor a drives the armature of a small shunt dynamoH, which supplies current to the field of a controllingcontinuous-current generator F through a reversing rheostat R, wherebythe electromotive force and direction of current supplied by the exciterH to the field of the generator F may be varied or reversed, as may bedesired. Thus, the armature of the generator F will be driven by themotor a at a practically constant speed in a field whose stren h can bevaried and its polarity reverse at will. The current, therefore,supplied by the generator F to the circuit wires 2, 3 will be of avariable and reversible electromotive force. The.

car B is likewise provided with an operating G Gr represent twocontinuous current generators driven from any suitable source of power,electrical oi mechanical, and which may be separated to any desiredextent, one, for example, being mounted on one of the cars, A,constituting a train, and the other on another of such cars, B, assumingthe invention to be utilized for the controlling of the propellingmotors of a train composed of aseries of motor cars. Thus, in Fig. 4, Iillustrate the generator G on the car A as being operated by a 3-phasemotor A, and the generator Gr on the car B as being operated by a3-phase motor A, as in 'Fig. 1. The fields of the continuous currentgenerators G" G are connectedin parallel with the circuit 2-3, wherebythe strength of such fields can be simultaneously varied and theirpolarity simultaneously reversed at will to permit such enerators tosupply currents of correspon ing electromotiveforce a'nddire'ction atall times. 7 The armature of the generator G is connected by a seriesparallel switch. K with..-..the armatures of the ;motors M M, and thearmature ofthe enerator Gr is connected by a series paralle switch Kwith the armatures of the propelling motors M M.- The series parallelcontrollin switches K and K are of any common orm,.by means of which thearmatures of the motors M M or -M M may be connected in series or inmeansof which the adjustment so effected can be varied when for anycause that is necessary, as for example when the wheels driven by thatparticular motor become 95 worn and of reduced diameter. A control.-ling rheostat 1" may also be mounted in the common circuit leading tothe fields of the two motors M M or M M for each locomotive, and bymeans of which both motors may simultaneously be varied when-desired, inorder that one locomotive as a unit may assume its desired orproportionate share of the load imposed on the train. A small rheostat rin the field circuit of the exciter H is also employed for thepurpose ofcontrollingthe electromotive force thereof.

' In operation, assuming the motors a a and generators G Gr to berotating at the proper approximately constant speed, and the handle ofeach of the rheostats R R to be in its central or neutral'position,current of constant electromotive force will be supplied, for example,by the exciter H to the circuit 1-2 to energize the fields of thepropelling motors M M the brushes of the exciter H being raised. Nocurrent will, however, energize the fields of the controlling generators-F F, and in consequence no current will be generated in the circuit 23,so that the fields of the generators G. and G? will not be e cited, saidgenerators will generate no curr%t, and the motors M M will therefore bea rest. By gradually fnoving the handle of the rheostat R for example,current in one direction or the other will 'be permitted to energize thefield of the controlling generator F with the desired polarity and withgradually increasing strength, whereby 'a current of graduallyincreasing electromotive force will be current" of gradually increasingelectromotive force will be generated by the generators G and G tosupply the motors M and M which will start to operate at a graduallyincreasing speed. In this Way, obviously, the speed of the motors M andhi can be, simultaneously controlled and the direction, oftheirarmatures reversed by eitherthe rheostat R or R or by means of anyother rheostat having 'tli'e capacity of varying the electromotive forceand the direction of current supplied to the circuit 2 3, it beingunderstoodthat the rheostats which are not operating are malnta-ined intheir neutral position and that the adjacent exciting generators H, H,etc., are out of circuit. Obviously, by connecting to the circuits 1- -2and 2*3a controlling apparatus comprising a motor a, an exciter H, acontrolling generator F and a rheostat R, as explained, the speed of thepropelling motors can be simultaneously controlled and the direction ofrotation of their armatures reversed from any other point on the circuitcomposed of the three wires 1, 2, 3.

Instead of varying the electromotive force of the controlling generatorF by producing variations in the field strengththereof, it will ofcourse be understood that the result can be secured in other waysfamiliar to those skilled in the art, as. for example by varying thespeed of rotation of the armature of the controlling generator or byreversing the sense of rotation thereof when a reversal of the polarityof the generators G and (l is desired.

In Fig. 5, I illustrate the connections which may be used in twoconnected cars when the original source of current is unidirectional andof constant eleotromotive force, and wherein may be employed a counterelectromotive force system (as I describe in my Patent No. 572903) forcon trolling the several motors. 12' represents a circuit of constantelectromotive force and of continuous current, and 3, 3, 4:, 4collecting devices carried by the two cars. On the car A is a shuntmachine A its field and armature being connected across the collectingdevices 3, 3, as shown. On the car B is a corresponding shunt machine Asimilarly connected. The machine A is mechanically connecte with thearmature of the dynamo electric machine 13'', and the machine A" ismechanically connected with the a rmature of the dynamo electric machineB. I have referred to these elements generally as shunt machines anddynamo electric machines because at some times they operate as motorsand at other times they operate as generators. Preferably the armaturesof the dynamos A and B and of A andB? are mounted on the sameshafts, asis common in the construction of motor generators. The armatures of thepropelling motors M and M respectively are connected, asshown, in serieswith the armatures of the dynamos A B and A, B, so that each of saidpropelling motors will be connected in a local loop 011 its respectivecar. Connecting the cars are the wires 1, 2,

3, 4, as in Fig. 1, 12 being a circuit ,Of

constant electromot-ive force and 34 a circuit of variable andreversible electromotive force, The circuit 12 is supplied byconnect1ons'1 2 from the source of supply, as shown, and each of thecircuits 1 -2 is provided with a reversing rheostat RR therein, bynieans of which the current in the circuit l-2 may be reversed in sensewhen it is desired to reverse the direction of rotation of thepropelling motors M, M The fields of said propelling 'motors ,areconnected across the circuit 12 as shown, so that said fields will be atall times energized by a can rent of constant electromotive force. Thecircuit 84 is supplied from the source of supply by wires 3 4 as shown,and in each of said circuits is a controlling rheostat R, R as shown, bymeans of which the amount and the direction of the current supplied tothe circuit 34 may be controlled. The operating handle of each of therheostats R, R is preferably arranged to be returned automatically bymeans of a spring or weight, as is common in the art, to the positionin. which the current supplied to the circuit 31 will energize thefields of the dynamo machines 13 and B whereby the eleetromotive forceof such dynamos will be equal and opposite to the line electromot-iveforce, so that in case of accident, the train will automatically come torest. In each circuit 3 '4 is mounted a circuit breaker DB arranged. tobe. manually opened or closed by the operator, while in circuit with thearmature of each'of te dynamo machines A f, A is a circuit breaker FDHof common form arranged to break the circuit when the supply voltagefails from any cause or when a current of objectionably high amperageinfluences the same. Shuntin each of the automatic circuit breakers FlBHis a resistance Res. In order to protectthe dynamos B B and the motorsM,

M from destructive currents, I also prefer- 'ablv place a circuitbreaker DH in each of witheach of the shunt machines A and- A. Thecontrollers R, B have beenmoved by their automatic springs so that thereis no resistance" in series with the fields of the regulating -mach'inesBi, B,'. and the connections are such that the electromot-ive force ofA, B and A, B will be counter to each other in the loops A-.- M and A--M". Assume now that the full electromot-ive-force is impressed' on themain circuit 12-: This excites the fields of the dynamos A, B A, B andof the motors M, M and the current will also flow 'througlrtheresistances Res. and the armatures of-the dynamos A, A". The dynamos AA, operating as motors, start into motion and accelerate both themselvesand the dynamos B, B. Since the dynamos A, B and A, B are operating infull fields and are counter to each other intheir respective loops,their full electromotive forces will be equal and opposite, and nocurrent will flow through the armatures of the motors M and M Hence nopower Wlll be consumed in bringing the dynamos A, B and A, B up to theirfull speed, except the friction load. Assuming t at the line voltage inthe circuit 1 -2 is 550 volts,that the resistances Res. are eaclr 2.5ohms, and that 20 amperes are required to operate the dynamos A A afterthey have been accelerated; then 50 volts will be dropped upon eachresistance, and the dynamos A, B and A, B will be producing nearly 500volts. The operator now closes the circuit breaker FDH on the car fromwhich the train is to be controlled, for example car A, cutting out theresistance and bringing up the dynamos A B to their full speed. Therewill still be no current of any 'consequence'in the loop A --B -M.' Theoperator ,now closes the circuit breakers FDH successively on the othercars of the train until the dynamos on those cars are also brought u tofull speed. a He next sees that. all the c rcuit breakers DB in serieswith the various controlling rheostats are open exc ept the'one inseries with the controlling "rheostat which he intends to use. If he hasbeen ,using a certain one and wishes to use another, he must first closethe V the operation.

circuit breaker DB at the controlling rheostat he intends to use, andthen open the cor responding circuit breaker at the controlling rheostathe is leaving, so that the fields of the'dyriamos B, B will not beopened in It will beseen that if this were done, the dynamos B and Bwould not generate a counter electromotive-force to the line, and hencethe full unbalanced line electromotive force would influence thepropelling motors M, M. To meet such a contingency'as this, I have madeuse of the automatic circuit breakers DH, as explained. By now operatingthe handle of the control- .the fields of the dynamos ling rheostat R,for examgle, on the car A, d and B can be similarly and simultaneouslyweakened, as I describe in my said patent, thereby reducing the counterelectromotive force generated by said dynamos and permitting current toflow through each of the local loops to correspondingly actuate thepropelling motors. When the entire resistance of the controllingrheostat R has been cut in, a further movement of the handle mayactually break the circuit 3 -4 so that no current will influence thecircuit 3-4, and the fields of the dynamos B, B will hence be nil. The Idynalnos B, B will therefore generate no counter elect-romotive force,and hence the full line voltage will be permitted to influence thepropelling motors, M, M. -By now moving the handle of the controllingrheostat R still farther, the direction of current in the circuit,34will be reversed and will be gradually increased in amount.- The dynamosB, B will therefore act as boosters, adding their electromotive force tothat of the line, so that when they are operatilig attheir maximum duty,the voltage applied to the motors M, M willbe practically double that ofthe lin'o voltage. When it is desircd to reverse the direction ofrotation of the propelling motors M, M, the result may be secured byoperating the reversing rheostat RR when the electromotive forces of Aand B are counter and approximately equal, which will reverse thecurrent in the circuit 1--2and thereby reverse the polarity of the motorfields. Instead of performin these operations, a rheostat may be placedin the field of each of the dynamos A A, so that by weakenin saidfields, the

electromotive force of the ynamos B, B

will exceed that of the dynamos A A, causcorresponding to thecontrolling rheostat of the'exciter H of Fig. 4. In other respects 'theconstruction and operation of the parts shown in this figure will beclear to those skilled in the art. a

It will be noted that my invention is mainly directed to such method andapparatus as will permit the use of high pressure transmission, and thatan advantage of importance is the greater ease in collecting the smallcurrent by the moving contacts.

It is evident that in carrying my invention into practice, that themotors and other parts of the apparatus may be designed forsuch voltageand current as is most suitable for their practical operation, and itwill be practicable and desirable in many instances to use diiferentmaximum voltages in the circuits of the two motor elements. Since theohmic resistance in the local circuit containing the generator and motorarmatures does not substantially aifect the voltage supo plied to themotor under change of current,

the .speed of the motors in a constant field will be practicallyproportionate to the net voltage in the local circuit and the currentwill automatically be in proportion to the torque.

Hencethe speed of the train will remain substantially constant Withoutchanging the controller in ascending a variable gradient. Similarly therate at which the train will descend a variable gradient will beconstant independent of a change of the controller, the currentgeneration. being automatically proportionate to the negative torquerepresented by the grade.

My method is applicable to any motors of the continuous current type andalso in many cases to' motors of other type. In using the termmotorsof-continuous current type, I intend to include all electricmotors having a commutator and in which under normal operationafterstarting, the working current in one element is commutated, whereby themotor is operative on direct, i11- terrupted or alternating current.

In someinstances the machines A and G need not necessarily be separatemachines,

since any known form of electric energy transformers may be employed,which will receive electric energy in any suitable form and deliversuitable electric energy of con- 40 trollable electromotive force,instead of the separate machines. In some instances, instead ofemploying dynamo electric generators for exciting the fields of thepropelling motors or for supplying other cir- 4 cuits used in theapparatus, other forms of current supply can be utilized, as for example primary or secondary batteries, thermo-electric generators, ormagneto machines. It will furthermore be understood that other forms ofgenerators and motors can be utilized from those shown, as for eX- amplethe generators may be compound wound-tha t is, may have the customaryseries compounding coil in addition to the heretofore described fieldwinding-and the motors may be series wound. Furthermore, it will beobvious that all known forms of series parallel control may be used inconnection with the motor armatures. It will also be understood thatinstead of reversing the rotation of the motor armatures by reversingthe current in the supplying generators therefor, the current suppliedby the generators may be maintained in a constant direction and areversing switch be inter- .motor M relative to another motor posedbetween the same and the motor armature for reversing thecurrent in thelatter, or the field of the motor may be reversed. -It will also appearfrom my description that-instead of operating the severalron'trollingmotors or the motorsfor driving the generators by electric energy,

mechanical motors for the purpose may be utilized, and that instead ofusing a 3-phase current as explained, a single-phase or any other formof alternating current or electric current adapted to produce another byinduction can be employed. For example, Fig. 7 illustrates a singlephase stationary source of energy at 10, supplying through suitableconnections the two conductors 11, 12 which in turn supply single phaseenergy to the cars as shown. The arrangement in other respectscorresponds to the disclosures of Fig. l.

In certain applications of my invention it may at times be desirable tooperate the .motors M, M at different speeds from those as to form ofcurrent or voltage, from elec-' trical energy not having suchcharacteristics provided that the energy delivered by the transformingmeans is delivered at a rate dependentupon the rate at which energy isdelivered to the transforming means.

Whenever I refer in the claims hereof to one element of the motor asbeing affected, do not necessarily mean that that element solely isaffected.

-Having now described my invention, what I claim as new and desire tosecure by Letters Patent is as folloWs-:

1. The method of controlling a plurality of electrically operatedvehicles in a tram,.

which consists in generating alternating current 7 energy, acceleratingthe vehicles thereby, generating alternating current energy to retardthe vehicles, supplying said latter energy to a, circuit, andcontrolling the current ina control circuit along the train forcontrolling aid acceleration and I retardation.

2-. The method of simultaneously and similarly controlling the speed oftwo electric motors working upon a common load, which consists ofgenerating in series with each of the motor armatures an independent andcontrollable electromotiye force, and varying the voltage of each ofsaid electromotive forces, while keeping the voltage of thetwo-electromotive forces always practiof the motor armatures anindepcndent elec-' tromotive force and changing and reversing thevoltage of each of sa1 electromotive forces, while keeping the voltageof the said electromotive forces always practically equal to each other.7

. 4. The method of controlling a plurality of electrically operatedvehicles in a train, which consists in accelerating the vehicles byenergy taken from the supply circuit, generating energy by the movementof the train and restoring energy to the supply circuit to retard thevehicles, and controlling the current in a control circuit connectingthe said different vehicles for controlling said acceleration andretardation.

5. The method of simultaneously and similarly controlling twoelectrically pro pelled vehicles in a train, which consists ofgenerating an alternating" current from a stationary source, leading thealternating current upon the train through moving contacts, transforminga part of such alternating current energy into unidirectional current,supplying the unidirectional current to one element of the severalmotors, and supplying to the other motor element electric energyindependent of the said unidirectional energy. y

6. he method of operating several electricall propelled vehicles in atrain, which consis s of generating current at a stationary source,leading upon the train energy represented by such current, transformingenergy' upon several different vehicles, supplying such transformedenergy to one or more elements of the propelling motors,andsimultaneously and similarly varying the e'lectrQ- motive forceof thetransformed energy.

. 7 The method of converting into electrical energy'the powerrepresented by a moving load, which consists in causing the moving loadto produce uni-directional'electrical energy, transforming suchuni-directional energy into alternating electrical en- 'ergy ofpractically constant electromotive force independent of the speed of themoving load, and supplying the alternating energy to a translatingdevice.

8. The method offoperating from a source of alternating current anelectric motor'at any desired speed from rest to the maximum, whichconsists in transforming such alternating currents into two independentunidirectional currents, supplying unidirectionalcurrentsto the twoelements of the motor, and varying the electromotive force of one oftheunidirectional currents.

9. The method of converting into electrical energy the power representedby retarding the moving load, which consists in causing the moving loadto produce electrical energy of different electromotive forces,transforming said electrical energy into electrical energy ofpractically constant electromotive force, and supplying said transformedenergy to an energy. consuming circuit. a

- 10. The I method of simultaneously and similarly controlling the speedof two electric motors working in unison, which consists of developingin series with each of the motor armatures an independent electromot1veforce, and changmg the voltage of each of said electromotive forces,while keeping the voltage of the two electromotive forces values.

11. The method of propelling and controlling a plurality of vehicles ina train,

always practically fixed in' their relative which consists in generatingelectrical energy afterward supplymg energy to another point of controland controlling from said other point the reverse movement of the trainby controlling the electromotive force of the energy supplied to saidmotor. v

12. The method of simultaneously and similarly controlling twoelectrically propelled vehiclesinfa train, which consists in generatingan alternating current from a stationary source, leading the alternatingcurrent upon the train by means of moving contacts, transforming a partof said alternati'ng current into unidirectional current, supplyingl'theunidirectional current, to one element of the motors and supplying tothe other element of said motors electric energy independent I of thesaid unidirectional energy.

13. The method of operating a plurality. I i

different vehicles, supplying such transformed energy to at least oneelement of the propelling motors, and simultaneously and simllarlyvarying the electromotive force 0 the transformed energy.-

14. The method of accelerating and retarding a movable vehicle whichconsists, while accelerating, in supplying to the vehicle alternatingcurrent energy at practically constant electromotive force, derivingtherefrom electric energy at a variable electromotive force and varyingthe speed of the vehicle by varying said variable electromotive forcesupplied to at least one element of electric motors located on differentvehicles of the train, and retardingsaid train by transforming theenergy represented bv the moving load into alternating current energy,and supplying such energy to an energy consuming circuit. 4

15. The method of operating a plurality of vehicles in a train,whichconsists in transmitting from a stationary source high pressure aternating current, leading such high pressure energy upon the train bymeans of moving contacts, deriving from such high pressure energy on thetrain electric energy at a lower and controllable electro-motive force,supplying the said low pressure energy to at "least one element of theplurality of motors located on said different vehicles, and varying theelectromot-ive force of said low pressure energy for the purpose ofvarying the speed of the motors.

16. The method of operating a plurality of vehicles in a train, whichconsists in transmitting from a stationary source high pressurealternating current electric energy, leadinghigh pressure energy uponthe train by means of moving contacts, deriving from such high pressureenergy on the train ielec t-ric energy of lower electromotive force,supplying energy to one point of control and controlling from said pointthe fori ward movement of the train by controlling 4 pressurealternating current electric energy,

the electromotive force of said low pressure energy for varying thespeed and forward rotation of'the motors, and afterward supplying energyto another point of control and controlling the reverse movement of thetr in from said other point by varying the electromot-ive force of saidlow pressure energy for varying the speed and reverse rotation of themotors.

17. The method of operating aplurality of vehicles in a train, whichconsists in transmitting from a stationary source high leading such highpressure energy upon the train'by means of moving contacts, derivingfrom said high pressure energy upon the train. electric energy of lowerand controllable electromotive force, supplying to at least one elementof a motor upon the train the said low pressure energy, varying thevoltage to vary the speed of the motor, and retarding the train bycausing-the motor to act as a generator and deliver electric energy intothe line.

18. Themethod of propelling and controlling a plurality of electricallyoperated vehicles in a train, which consists in gen-- erating electricenergy upon a plurality of vehicles of the train, supplying said energyto one element of each propelling motor, supplying energy to one pointof control and controlling from said point the forward stationarysource, leading said energy upon the train, producing by magneticinduction in a local circuit upon the train, electrically insulated fromthe supply line, a controllable electromotive force, and varying theelectromotive force in said local circuit for the purpose of varying thespeed of the motors, and causing the motors to act as generators in saidlocal circuit for the purpose of bringing the car to rest and recircuitclosed.

20. The method of operating a vehicle, which consists in generatingsingle phase alternating current at relatively high pressure and smallcurrent at a stationary source, leading small current at high pressurethrough moving contacts upon the vehicle, deriving therefrom electricalenergy at'a reduced voltage, and supplying such energy to one element ofthe propelling motor, and supplying to the other element of the motorelectric energy at an electromotive force different from that suppliedto the first element of the motor.

21. The method of operating a vehicle, which consists in generatingsingle phase alternating current at relatively high pressure and smallcurrent at a stationary source, leading said small current at highpressure through moving contacts upon the vehicle, deriving therefrom intwoindependent circuits electric ene y at different electromotiveforces, and energizing the two elements of the motor thereby.

22. The method of propelling one or more I versing while continuouslymaintaining said vehicles, which consists in generating alternatingcurrent energy at relatively .hi'gh pressure and small current at astationary sour'ce, leading'said energy at high pressure through movingcontacts upon thevehicle, deriving therefrom electric energy at lowpressure and supplying the same to one element of the propelling motor,and also independently deriving electric energy at low pressure andsupplying the same to another elementof the propelling motor.

23. The method of propelling a plurality of vehicles by a plurality ofelectric motors, which consists in generating alternating current energyat relatively high pressure and small current at a stationary source,leading said energy at high pressure through moving contacts upon thevehicles, derivmg therefrom electric energy at low pressure andsupplying the same to one element of each of the propelling motors, andalso.

which consists in generating alternating current energy atrelatively-high pressure and small current at'a stationary source,leading energy at high pressure through moving contacts upon thevehicles, deriving therefrom electric energy at low, pressure andsupplying the same to one element of each of the propelling motors, andalso deriving electric energy at low pressure and supplying the same toanother element of each of the propelling motors, supplying energy toone point of control and controlling the forward movement of saidvehicles from said point by simultaneously and similarly controlling theelectromotive force of the energy supplied to one element of each of themotors, and afterward supplying energy to another point of control andcontrolling the reverse movement of said vehicles from said other pointby simultaneously and similarly controlling the electromotive force ofthe energy supplied to one element of each of the motors.

25. The method of converting into -electrical energy the powerrepresented by a moving train comprising a plurality of vehicles each ofsaid vehicles having a propelling motor which consists in causing themotors to simultaneously generate electric energy at. varying speeds ofthe motors,

' transforming such energy and controlling the electromotive force of"such transformed energy, and delivering the transformed energy to anenergy consuming circuit.

26. The method of operating a plurality of electrically propelledvehicles, which consists in generating electric energy at a stationarysource, leading energy upon the vehicles, transforming electric energyon the different vehicles, and simultaneously and similarly controllingthe electromotive force of said derived energy on the vehicles forvarying the electromotive force utilized in at least one element of themotor. 4

27. The method of operating a plurality of electrically propelledvehicles, which consists in generating electric energy at a stationarysource, leading energy upon the vel1icles,'transforming the electricenergy on the different vehicles, supplying energy to one point ofcontrol and controlling the for- .trolling the electromotive force 0.element of the motor.

28. The'method of operating a plurality of electrically propelledvehicles, which consists in generating electric energy at a stationarysource, leading energyupon the vehicles, transforming the electricenergy on 'the difierent vehicles, supplying such transformed energy toa plurality of electric motors, and simultaneously and similarl consaidtransformed energy on the vehicles for varying the electromotive forceapplied to the said motors.

29. The method of operating an electric motor, which consists ingenerating high tension single phase energy, transforming,

such'energy into energy of lower electromotive force and larger current,supplying such energy of lower electromotive force through a revolvingcommutator to at least one element of the motor, supplying energy to onepoint of control and controlling from said point the rotation of themotor 'in one direction by controlling the electromotive force suppliedto said element, supplying energy to another point of control andcontrolling the rotation of the motor in the opposite direction fromsaid other point by controlling the electromotive force of the energysupplied to said motor.

30. The method of operating an electric motor, which consists ingenerating high tension single phase energy, transforming such energyinto energy of lower electromotive force and larger electric current,

' supplying such energy of lower electromotive force to at least oneelement of' the motor, commutating thecurrent so supplied, supplyingenergy to one point of control and controlling from said point the speedof rotation of the motor in one direction by controlling theelectromotive force supplied to said element, retarding the motor bycausing it to generate electric energy, supplying energy to anotherpoint of control and controlling from said other point the speed ofrotation of the motor in the opposite direction by controlling theelectromo tive force supplied to? said element, and retarding the motorby "causing it to generate electric energy.

Y 31. Themethod of operating an electric motor, which consists insupplying energy to at least one element of the motor, commutating thecurrent so supplied, supplying energy to one point of control andcontrolling from said point the speed of rotation of the motor in onedirectionby controlling the electromotive force of the energy suppliedto said motor, and afterward supplying energy to another point ofcontrol and controlling from said other point the speed of the motor inthe opposite direction b controlling the electromotive force of t eenergy supplied to the motor.

32. The method of operating an electric motor at varying speeds, whichconsists in supplying its armature from a generator, exciting the fieldof the generator from a separate source of electromotive force andvarying the electromotive force-of said separate source.

33. The method of operating an electric motor, which consists insupplying its armature from a genera-tor, exciting the field of thegenerator from a separate source, and

varying and reversing the electromotive force of said separate source.

34. The method of operating an velectrically propelled train comprisingone or more vehicles, which consists in generating high tension singlephase energy, conducting high tension single phase energy upon thetrain, transformin on the train such energy into energy of su cientlylow tension to be readily commutated, dividing said energy into aplurality of divisions, supplying each of said divisions of low tensionenergy to at least one element of its respective electric motor,commutating the current of each division, and varying the speed of thetrain by varying the net efi'ective electromotive force of the said lowtension energy.

35. The method of operating an electrically propelled vehicle, whichconsists in generating single phase alternating electric energy at astationary source, transmitting such energy in the form of high tensionsingle phase energy, leading single phase energy upon the vehiclethrough moving contacts, transforming on the vehicle single phase energyinto low tension energy, supplying such low tensiom'energy to atleastone element of the propelling electric motors, commutating thecurrent of said low tension energy, and varying the speed of said motorsby varying the net effective electromotive force of said low'tensionenergy.

36. The method of retarding an electrically propelled vehicle, whichconsists in generating in the revolving windings of a plurality ofdynamo electric machines, each mechanically gonnected to its respectiveaxle, low tension electric energy, commutating the current so generatedby each dynamo electric machine, transforming the energy into energyhaving high tension single phase alternating current, then conductingthe high tension single phase energy through moving contacts to a hightension single phase supply circuit, and utilizing the said generatingat a stationary source alternating current energy, transmitting the enerderived from said source to the vehicle in the form of high tensionalternating current energy, conducting high tension energy upon thevehicle through moving contacts, transforming such energy on the vehicleinto low tension energy, supplying low tension energy to a plurality ofmotors which divide the total load between them, and varying the speedof the vehicle by varying the e ective electromotive force of the energysupplied to said motors.

38. The method of operating an electrically propelled train, whichconsists in generating at a stationary source alternating currentenergy, transmittin the energy derived from the said source to the trainin the form of high tension alternating current energy, conducting hightension energy upon the train through moving contacts, transformforproducing a current in a controlling circuit, transmitting current insaid circuit to another of the vehicles,'and controlling from said othervehicle the current in said circuit and thereby control the movement ofthe train.

40. The method of controlling an electrically propelled train,comprising a plurality of vehicles, which consists in producing on oneof "the vehicles electric energy for propelling the train, supplying acurrent to a controlling circuit on one of the vehicles, transmittingcurrent in said circuit to another of the vehicles, controlling fromsaid other vehicle the current in said circuit and thereby controllingthe said electric energy for propelling the train.

41. The method of operating an electrically propelled train, whichconsists in leading alternating current electric energy of substantiallyconstant electromotive force upon the train through moving contacts,transforming said energy into energy of different electromotive forcesfor operating the train at difi'erent'speeds, producing on the train anelectromotive force which is independent of said other electromotiveforces, and controlling a current due. to'said independent electromotiveforce for-controlling said different electromotive forces and therebycontrolling the speed of the train.

42. The method of operatingan electrielectromotive force for varying theelectromotive forces of said unidirectional energy and therebycontrolling the speed of the train. v l

43. The method of operating a plurality of vehicles in a train, whichconsists in transmitting high pressure energy from a stationary source,leading energy upon the train, producing in a local circuit uponthetrain a controllable electromotive force, and varying the electromotiveforce in said local circuit for the purpose of varying the speed of themotors, and causing the motors to act as generators in said localcircuit for the purpose of bringing the train to rest and reversingwhile continuously maintaining said circuit closed.

44:. The method of operating a vehicle, which consists in generatingelectric energy at relatively high pressure and small ci1rrent at astationary source, leading high pressure energy through moving contactsupon the vehicle, deriving therefrom electrical energy at a reducedvoltage, and supplying such energy to one element of the propellingmotor, and supplying to another I. element of the motor electric energyat an electromotive force different from that sup-- plied to the firstelement of the motor.

45. The method of operating a vehicle, 'which consists in generatingcurrent at relatively high pressure and small current at a stationarysource, leading small current at high pressure through moving contactsupon the vehicle, deriving therefrom in two independent circuitselectric energy at different electromotive forces, and energizing thetwo elements of the motor thereby.

46. The method of propelling a plurality of vehicles by a plurality ofelectric motors, which consists in generating alternating current energyat relatively high pressure and small current at a stationary source,leading energy at high pressure through moving contacts upon thevehicles, deriving therefrom electric energy at low pressure andsupplying the same to one element of ,each of the propelling motors, andalso independently deriving electric energy at low pressure andsupplying the same to another element of each of the propelling motors,controlling the forwardmovement of said vehicles by simultaneously andsimilarly controlling the electromotive force. of the energy supplied toone element of each of the motors, and controlling the reversev movementof the vehicles by simultaneously and slmllarly controllingtheelectromotive force of the energy supplied to one elemen of each ofthe motors.

47. The method of train control which consists in developing a.separateelectromotive force .upon each of a plurality of locomotiveunits in a train, and varying simultaneously the voltage applied to atleast one element of the propelling motors of each of said unitsbysimultaneously varying each 0 said electromotive forces. i

48. The method of operating a train, which consists in generat ngelectric energy at a stationary source, transmitting electric energy tothe train, leading electric energy upon the train by means of movingcontacts,

transforming the energy into a plurality of divisions on differentlocomotive units of the train, supplying said divisions of the energy toat least one element of the motors of the respective locomotive units,and simultaneously controlling the transformed energy to controlthetrain.

49. The method of controlling aplurality of motors actin on a commonload, which consists in simultaneously controlling a plurality ofinductively acting voltage regulators in series with each of the motorsrespectively.

50. The method of controlling a plurality of motors acting on a commonload, which consists in controlling the energy in a control circuit, andthereby controlling a plurality of electromotive forces in series witheach of the motors respectively.

51. The method of controlling a plurality of motors acting on a commonload, which consists in dividing the energy into a plurality ofdivisions, varying the electromotive force of the divisions, andsupplying the resultant energy of variable electromotive force of eachdivision to its corresponding motor.

52. The method of operating a. train which consists in developing aseparate elec tromotive force upon each of a plurality of locomotiveunits in a train, and controlling the power at various speeds bysimultaneously varying eachof said electromotive forces in series .withthe propelling motors of each of said units.

53. Themethod of operating .a train which consists in generating energyat a stationary source, leading energy on the train. by moving contacts,creating on the train a plurality of electromotive forces,

each of said electromotive forces being variable, supplylng at leastone.element ofthe propelhng motors from each of said sourcesrespectively, and simultaneously varying the speed of the motors bysimultaneously varying the electromotive forces applied to correspondingelements of the motors.

54. The method of reversing an electric motor, which consists insupplying its armature from a. generator, supplying the field of thegenerator from a separate Source of electromotive force, and reversingthe direction of the electromotive force of said separate source.

55. The method of controlling a. plurality nating current energy toretard the vehicles and sup-plying said latter energy to a circuit,

transmitting electric control energy along the train and controllingsaid electric control energy for controlling said acceleration andretardation.

57. The method of controlling a plurality of electrically propelledvehicles in a train, which consists 1n generating alternating currentenergy, accelerating the vehicles thereby, generating alternatingcurrent energy to retard the vehicles, supplying said latter energy to acircuit, and controlling the ourrent in a lower tension control circuitalong the train for controlling said acceleration andretardation.

58. The method of controlling a plurality of electricallyoperatedvehicles in a train,

which consists in generating alternating cur-' rent energy, acceleratingthe vehicles thereby, generating alternating current energy to retardthe vehicles, supplying said latter energy to a circuit, and controllingunidirectional currentin a control circuit along the train forcontrolling said acceleration and retardation.

59. The method of controlling a plurality of electrically operatedvehicles in a train, which consists in accelerating the vehicles byenergy taken from-the supply circuit,

generating energy by the movement of the train and restoring energy tothe supplycircuit to retard the vehicles, transmitting control energyalong the train, and controlling said control energy for controllingsaid acceleration and retardation.

60. The method of controlling a plurality which consists in generatingalternating cur; rent energy, acceleratin the vehicles thereby,generating' alternating current energy to retard the vehicles, supplyingsaid latter energy to a circuit, supplying current to the controlcircuit along the train from a separate source of electromotive force onthe train,'and controlling the current in said control circuit along thetrain for control ling said acceleration and retardation.

61. The method of operating a motor at dlfierent speeds, which consistsin supplying its armature from a dynamo electric generator, supplyingits field winding and the field winding of said generator from twosources of electromotive force respectively,

and "developing difierent voltages at the source of supply for thegenerator field winding.

62. The method of operating an electric motor at different speeds, whichconsists in supplying its armature from a dynamo electric generator,supplying its field winding and the field winding of said generator fromtwo sources of electromotive force respecof electrically operatedvehicles in a train tively, ai1d.varying and reversing the electromotiveforce of one of said sources.

63. The method of operating an electric motor at different speeds, whichconsists in' supplying its armature from a dynamo electric generator,supplying its field winding and the field winding of said generator fromtwo sources of electromotive force respec tively, and reversing thedirection of the electromotive force of that source from which the fieldof the generator is energized.

64. The method of operating an electric motor at difierent speeds, whichconsists in l supplylng its armature from a dynamo electric generator,supplying a field winding of the motor and a field winding of saidgenerator from two sources of electromotive force respectively, anddeveloping different electromotive forces ,in the circuit of thegenerator field winding.

65. The method of operating a motor from rest to a high speed, whichconsists in supplying its armature from a generator,

exciting the field of the, generator from a separate source ofelectromotive force, energizing a field winding of the motor from aseparate source of electromotive force, and

varying the effective electromotive force-in the circuit of saidgenerator field winding fromsubstantially zero to a maximumelectromotive force. i

66. The method of controlling an electric motor, which consists insupplying it from a generator, energizing the field of the generatorfrom a separate source-of current,

var ing the voltages of said generator and sai separate source, andreversing the current supplied to the generator field magnet from theseparate source of current formversing the motor.

67. The method of o eratin an electr c motor at different spee s, whicconsists in generating electric energy at a variable and controllableelectromotive force, supplying said energy to a controlling circuit andto a plurality of electromagnetic controlling windings varying the saidelectromotive force independently of said windings to vary the magneticeffect of said windings, and controlling thereby the energy supplied toat least one of the elemental Windings of the motor.

(58. The method of operating a motor at different speeds, which consistsin generating different electromotive forces in a controlling circuitand thereby varying the effect of electromagnetic windings and therebyvarying the electromotive force of the energy delivered to the motor.

69. The method of operating a motor at different speeds, which consistsin generating different electromotive forces in a control circuit,controlling thereby the electro- 'motive force of a source ofelectromotive force, and supplying the energy from said source atdifferent electromotive forces to at least one of the motor windings.

70. The method of electrically controlling a train comprising aplurality of lo comotive units, which consists indeveloping electricenergy upon each of a plurality of the locomotive units, dividing thetotalduty of each of said locomotives between a plu'- rality of motorarmatures, and varying the voltage of the energy supplied to each of themotors by varying control energy supplied to the said plurality ofunits.

71. The method of accelerating a train which consists in generating hightension electric energy at a stationary source, transforming said energyto energy of lower electromotive force and supplying said transformedenergy to a working conductor, conducting said transformed energy fromthe working conductor upon the train, transforming the energy upon thetrain into a plurality of divisions, and supplying energy from saiddivisions at gradually increasing electromotive forces to a plurality ofelectric motor windings connected in parallel with each other on each ofa plurality of locomotives in the train.

72. The method of electrically operating.

a train, which consists in causing the development by magnetic inductionof a plurality of different electromotive forces successively upon eachof a plurality of units in said train, supplying energy dependent uponsaid different electromotive forces upon' each such unit to a pluralityof propelling ergy upon said units to simultaneously control said energyand thereby control the propulsion of the train.

73. The method .of electric locomotive control which consists in derivinelectric energy from a common source 0 electromotive force on the train,supplying energy from said source on the train to a 'plurality of motorarmature windings connected in parallel relatively to said source, andseparately exciting the field windings of said motors corresponding tosaid armature windings. y

7 4. The method of electric locomotive con-' trol, which consists ininductively developing electric energy upon the locomotive, supplyingsaid energy at the voltage at which it is developed to each of thearmature windings of a plurality of electric motors Working on a commonload; separately exciting said motors, and varying the electromotiveforce of the energy developed on the locomotive to cause the jointaction of the motors to start the locomotive, whereby the tractiveeffort of each motor is substantially independent of another motor.

75. The method of operating a train which consists in generatingelectric energy at a stationary source, conducting electric energy in apluralit of divisions through a plurality of moving contacts upon thetrain, transforming each of said divisions of the energy on the train,controlling by a common control the several divisions of the energy,supplying the controlled divisions of energy to corres onding tractiveelectric motors, and employing common control enmotors, and simutaneously varying the voltage of the several divisional energies to varythe speed of the train.

76. The method of starting a vehicle from rest which consists inproducing electric energy on the vehicle, supplying energy to aplurality of motor armature windings connected to produce torquesindependent of each other, separately exciting a field windingcorresponding to each of said armatures, and varying the electromotiveforce-of the energy supplied to the armatures whereby the tractiveeffort produced by each motor is produced independently of a change inthe tractive effort produced by another motor.

77. The methodof starting an electrically propelled train from restwhich consists in generating electric energy at a stationary source,conducting energy upon the train, transforming energy upon the train andsupplying energy at the transformed voltage to the armature windings ofeach of a plu- V rality of propelling motors while at rest, andseparately exciting corresponding field windings of said motors.

78. The method of operating an electrically propelled train, whichconsists ingen-

